Primary squamous cell carcinoma arising in the liver: A case report and review of literature

Figure 1 Serial contrast-enhanced computed tomography findings during treatment and follow-up. A-C: Baseline liver computed tomography (CT) obtained on October 23, 2022, including the noncontrast phase (A), the arterial phase (B), and the portal venous phase (C), showing a large heterogeneous lesion predominantly involving the left hepatic lobe; D-F: Follow-up CT obtained on July 24, 2023, including the noncontrast phase (D), the arterial phase (E), and the portal venous phase (F), showing a marked reduction in the size of the target lesion; G-I: Follow-up CT obtained on March 10, 2024, including the noncontrast phase (G), the arterial phase (H), and the portal venous phase (I), showing enlargement of the target lesion. The measurement lines in panels C, F, and I indicate the longest diameter of the selected target lesion used for retrospective Response Evaluation Criteria in Solid Tumors version 1.1 assessment; J-L: Additional CT images obtained at a different axial level on March 10, 2024, including the noncontrast phase (J), the arterial phase (K), and the portal venous phase (L), demonstrating newly developed intrahepatic lesions. Orange arrows indicate representative newly developed intrahepatic lesions.

Figure 2 Histopathological and immunohistochemical features of the liver biopsy specimen. All hematoxylin and eosin (H&E) and immunohistochemical panels were obtained from the same biopsy specimen. A: H&E staining shows abundant tumor cells (original magnification, × 200); B: Immunohistochemistry shows diffuse nuclear positivity for p63 (original magnification, × 400); C: Nuclear positivity for p40 (original magnification, × 400); D: Cytoplasmic positivity for cytokeratin 5/6 (CK5/6; original magnification, × 400). The combined expression of p63, p40, and CK5/6 supports squamous differentiation of the tumor.

Figure 3 Whole-body 18F-fluorodeoxyglucose positron emission tomography/computed tomography images. A: Axial positron emission tomography image shows increased 18F-fluorodeoxyglucose (18F-FDG) uptake in the hepatic lesion; B: Axial computed tomography (CT) image shows the corresponding hepatic lesion; C: Fused 18F-FDG positron emission tomography/CT image localizes the hypermetabolic activity to the liver; D: Maximum-intensity projection image shows increased metabolic activity confined to the hepatic region, with no definite evidence of an extrahepatic hypermetabolic malignancy.